Experiments on CO2-water bubble flows in a vertical pipe were carried out for clean water, an aqueous NaCl solution, and an aqueous NaCl solution with 1-octanol to obtain databases of spatial evolutions of the flows with the impurities. Mass transfer correlations for bubbles in these liquids were implemented into a one-way bubble tracking method. Numerical predictions of the spatial evolution, e.g., transition from a bubbly to a slug flow, depending on the impurities agreed well with the experiments.